Using ion-exchange electrodes, Specific Aims are: (1) To define the thermodynamic properties of calcium-binding to serum albumin in normal subjects and in patients with: (1) stable cirrhosis, (2) progressive cirrhosis, (3) chronic active hepatitis, and (4) fulminant hepatitis. Our hypothesis is that the diseased hepatocyte may synthesize faulty albumin as suggested by previous calcium-binding studies in this laboratory. (2) To further define the relationship between calcium-binding and specific protein conformational states in each of the above groups using circular dichroism (CD) and optical rotatory dispersion (ORD). The hypothesis to be tested is that, upon dissociation of the last Ca ions from the albumin molecule (as in severe hypocalcemia), the albumin molecule loses all affinity for Ca ions (K'a double bond O), a phenomenon which we have termed "The Clam Effect". We postulate that "The Clam Effect" is related to closing of an a-helix upon dissociation of the last Ca ions from the albumin molecule. (3) To continue similar studies with purified human albumin, uing Ca ions electrodes and circular dichroism. (4) To similarly study the binding of magnesium, as outlined above for Ca ions using an ion-exchange ("water hardness") electrode with about equal selectivity for Ca ions and Mg ions. A Ca ions electrode will be used as the reference electrode in these studies for subtraction of the Ca ions component of the total electrode potential.